Media Galleries API - Picasa: Change PMP Parsing to deal with PlatformFile.

chrome/browser/media_galleries/fileapi/picasa/pmp_column_reader.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_PICASA_PMP_COLUMN_READER_H_
 #define CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_PICASA_PMP_COLUMN_READER_H_
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/platform_file.h"
 #include "chrome/browser/media_galleries/fileapi/picasa/pmp_constants.h"
 
 namespace base {
 class FilePath;
 }
 
 namespace picasa {
 
 // Reads a single PMP column from a file.
 class PmpColumnReader {
  public:
   PmpColumnReader();
   virtual ~PmpColumnReader();
 
   // Returns true if read successfully.
   // |rows_read| is undefined if returns false.
-  bool Init(const base::FilePath& filepath, const PmpFieldType expected_type,
-            uint32* rows_read);
+  bool Init(const base::PlatformFile& file,
+            const PmpFieldType expected_type);
 
   // These functions read the value of that |row| into |result|.
   // Functions return false if the column is of the wrong type or the row
-  // is out of range.
+  // is out of range. May only be called if successfully initialized.
   bool ReadString(const uint32 row, std::string* result) const;
   bool ReadUInt32(const uint32 row, uint32* result) const;
   bool ReadDouble64(const uint32 row, double* result) const;
   bool ReadUInt8(const uint32 row, uint8* result) const;
   bool ReadUInt64(const uint32 row, uint64* result) const;
 
+  // May only be called if successfully initialized.
+  uint32 rows() const;
+
  private:
-  bool ParseData(const PmpFieldType expected_type, uint32* rows_read);
+  bool ParseData(const PmpFieldType expected_type);
   // Returns the number of bytes parsed in the body, or, -1 on failure.
   int64 IndexStrings();
 
   // Source data
   scoped_ptr<uint8[]> data_;
   int64 length_;
 
   // Header data
   PmpFieldType field_type_;
   uint32 rows_;
 
   // Index of string start locations if fields are strings. Empty otherwise.
   std::vector<const char*> strings_;
 
   DISALLOW_COPY_AND_ASSIGN(PmpColumnReader);
 };
 
 }  // namespace picasa
 
 #endif  // CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_PICASA_PMP_COLUMN_READER_H_